Chair with pivotable chair back

ABSTRACT

A chair comprises a frame, a chair back, and a chair back return device. The chair back is mounted to the frame for pivotable movement away from a home position. The chair back return device is arranged to return the chair back to the home position.

BACKGROUND

The present disclosure relates to chairs. More particularly, the present disclosure relates to chairs with chair backs that are able to pivot.

Chairs typically have chair backs. A chair back is used to support the back of a person sitting on the chair.

SUMMARY

According to the present disclosure, a chair is provided. The chair comprises a frame and a chair back. The chair back is mounted to the frame for pivotable movement about a pivot axis in opposite directions from a home position. A chair back return device is used to return the chair back to the home position.

The frame includes left and right chair back mounts. A left side of the chair is mounted to the left chair back mount. A right side of the chair is mounted to the right chair back mount.

The chair back return device includes a left return spring and a right return spring. The left return spring is mounted to the left chair back mount to engage a left tab included in the left side of the chair back. The right return spring is mounted to the right chair back mount to engage a right tab included in the right side of the chair back. The left and right return springs act against the left and right tabs to pivot the chair back to return the chair back to the home position.

Additional features and advantages of the apparatus will become apparent to those skilled in the art upon consideration of the following detailed description exemplifying the best mode of the disclosure as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description particularly refers to the accompanying figures in which:

FIGS. 1-3 are perspective views showing a chair including a chair back coupled to left and right chair back mounts included in a frame of the chair for pivotable movement of the chair back about a pivot axis between a home position shown in FIG. 1 and a rearward-leaning pivot position shown in FIG. 2 and a forward-leaning pivot position shown in FIG. 3;

FIG. 4 is an exploded perspective view showing components of the chair back in the middle of the page, components of the left and right chair back mounts on the left and rights sides of the page, and somewhat U-shaped left and right return springs between the chair back and the left and right chair back mounts for returning the chair back to the home position from the rearward-leaning and forward-leaning pivot positions;

FIG. 5 is a sectional view taken along lines 5-5 of FIG. 1 showing the chair back in its home position and showing a tab that is included in the left side of the chair back and positioned between and in engagement with rear (on the left) and front (on the right) spring flanges of the left return spring;

FIG. 6 is a sectional view taken along lines 6-6 of FIG. 2 showing the chair back pivoted in a rearward direction to its rearward-leaning pivot position and showing engagement between the rear spring flange of the left return spring and a rear pivot limiter to limit pivotable movement of the chair back in the rearward direction;

FIG. 7 is a sectional view taken along lines 7-7 of FIG. 3 showing the chair back pivoted in a forward direction to its forward-leaning pivot position and showing engagement between the front spring flange of the left return device and a front pivot limiter to limit pivotable movement of the chair back in the forward direction, and

FIG. 8 is a rear elevational view, with portions broken away, showing the chair back mounted on the left and right chair back mounts;

DETAILED DESCRIPTION

A chair 10 is shown in FIG. 1. The chair 10 includes a chair back 12 mounted to a frame 14 for pivotable movement relative thereto about a pivot axis 16. The chair back 12 is pivotable from a home position shown in FIGS. 1 and 5 in a rearward direction 18 to a rearward-leaning pivot position shown in FIGS. 2 and 6 when, for example, a person sitting on the chair 10 leans rearward or backward. The chair back 12 is also pivotable from the home position in an opposite, forward direction 20 to a forward-leaning pivot position shown in FIGS. 3 and 7 when, for example, a person sitting on the chair 10 leans forward.

The chair 10 includes a chair back return device 22, as shown in FIG. 4. The chair back return device 22 is arranged to return the chair back 12 to the home position from the rearward-leaning and forward-leaning pivot positions, as discussed in more detail herein.

The frame 14 includes a front leg unit 24 and a rear leg unit 26, as shown in FIGS. 1-3. The front and rear leg units 24, 26 are coupled to one another for pivotable movement between an unfolded position (shown in FIGS. 1-3) for use of the chair 10 and a folded position (not shown) for storage of the chair 10. A seat 28 is mounted to the frame 14 for pivotable movement as the front and rear leg units 24, 26 are pivoted between the unfolded and folded positions.

The front leg unit 24 includes left and right frame members 30, 32 and left and right chair back mounts 34, 36, as shown in FIGS. 1-4 and 8. In the illustrated embodiment, the frame members 30, 32 are legs. A leg receiver 37 of the left chair back mount 34 is mounted to a top portion 38 of the left frame member 30. A leg receiver 37 of the right chair back mount 36 is mounted to a top portion 38 of the right frame member 32.

The chair back 12 is positioned between and mounted to the left and right chair back mounts 34, 36 for pivotable movement about the pivot axis 16 in the rearward and forward directions 18, 20, as shown in FIGS. 1-3 and 8. A left side 40 of the chair back 12 is mounted to a left axle 42 of the left chair back mount 34. A right side 44 of the chair back 12 is mounted to a right axle 46 of the right chair back mount 36. The left and right axles 42, 46 cooperate to define the pivot axis 16. Front and rear sides 47, 49 of the chair back 12 extend between the left and right sides 40, 44.

The chair back return device 22 is arranged to engage at least one of the left and right sides 40, 44 of the chair back 12 to pivot the chair back 12 to return the chair back 12 to the home position from the rearward-leaning and forward-leaning pivot positions. Stated otherwise, the chair back return device 22 provides return means for engaging at least one of the left and right sides 40, 44 of the chair back 12 to pivot the chair back 12 to return the chair back 12 to the home position from the rearward-leaning and forward-leaning pivot positions.

The chair back return device 22 includes a left return spring 48 and a right return spring 50, as shown in FIG. 4. The left return spring 48 is mounted to a spring mount 52 included in the left chair back mount 34 and is arranged to engage a left motion transmitter 55 included in the left side 40 of the chair back 12, as shown in FIGS. 5-7. The right return spring 50 is mounted to a spring mount 52 included in the right chair back mount 36 and is arranged to engage a right motion transmitter 57 included in the right side 44. Each spring mount 52 is mounted to a generally cone-shaped shroud 53 which surrounds the spring mount 52 and the return spring 48, 50 mounted thereto. The motion transmitters 55, 57 are arranged to transmit motion between the return springs 48, 50 and a back rest 59 included in the chair back 12, as discussed in more detail herein.

Each return spring 48, 50 includes a flange mount 54 and relatively movable rear and front flanges 56, 58, as shown in FIG. 4 with respect to both return springs 48, 50 and shown in FIGS. 5-7 with respect to return spring 48. The flange mount 58 is mounted to an annular flange mount base 60 included in a spring mount 52. Each flange mount base 60 is formed to include an axle channel 64 through which one of the axles 42, 46 extends. In the illustrated embodiment, the flange mount 58 is C-shaped and fits over the flange mount base 60. The flanges 56, 58 extend radially outwardly from the flange mount 54 and are circumferentially spaced from one another.

Each motion transmitter 55, 57 includes a disk-shaped tab mount 64 and a tab 66 mounted thereto for engagement with a spring 48, 50, as shown in FIG. 4. Each tab mount 64 is formed to include an axle-receiving opening 68. The left axle 42 extends through the axle-receiving opening 68 formed in the tab mount 64 of the left motion transmitter 55 into an axle-receiving opening 70 formed in a front shell member 72 of the back rest 59. The right axle 46 extends through the axle-receiving opening 68 formed in the tab mount 64 of the right motion transmitter 57 into an axle-receiving opening 70 formed in the front shell member 72.

A pair of transmitter retainers 74 shown in FIG. 4 are mounted to an axially inner side of each tab mount 64. The retainers 74 extend into corresponding retainer receivers 76 formed in the front shell member 74 so that the motion transmitters 55, 57 and the back rest 59 pivot with one another.

An aesthetic portion 78 shown in FIG. 8 is mounted to the axially inner side of each tab mount 64. Each aesthetic portion 78 extends into a recess 80 formed in a rear shell member 82 included in the back rest 59. The front and rear shell members 72, 82 are coupled to one another by fasteners 84 shown in FIGS. 4-7 to provide the back rest 59.

Interaction between the left return spring 48 and the tab 66 of the left motion transmitter 55 is shown in FIGS. 5-7. The following discussion of such interaction applies also the right return spring 50 and tab 66 of the right motion transmitter 57.

The tab 66 extends between the rear and front flanges 56, 58. The tab 66 is positioned radially outwardly from a flange stop 86 that is included in the spring mount 52 and extends radially outwardly from the flange mount base 60. In the home position of the chair back 12, the tab 66 engages both flanges 56, 58 and both flanges 56, 58 engage the flange stop 86, as shown in FIG. 5.

The tab 66 engages the rear flange 56 and disengages the front flange 58 when the chair back 12 is pivoted in the rearward direction 18 to the rearward-leaning pivot position by a rearward pivot force 88, as shown in FIG. 6. The tab 66 pivots the rear flange 56 in the rearward direction 18 away from the front flange 58 which remains engaged with the flange stop 86, thereby rearwardly loading the return spring 48.

A rear pivot limiter 87 is arranged to limit pivotable movement of the chair back 12 in the rearward direction 18, as shown in FIG. 6. The rear flange 56 extends between the rear pivot limiter 87 and the tab 66 so that the rear pivot limiter 87 engages the rear flange 56 to limit such rearward pivotable movement. In the illustrated embodiment, the rear pivot limiter 87 is a wall mounted to and extending radially inwardly from the shroud 53.

The rearwardly loaded return spring 48 returns the chair back 12 to the home position when the rearward pivot force 88 is removed from the chair back 12. The rear flange 56 engages the tab 66 and moves toward the front flange 58 to apply a force thereto to pivot the chair back 12 in the forward direction 20 to return the chair back 12 to the home position from the rearward-leaning pivot position. The rear flange 56 re-engages the flange stop 86 upon return of the chair back 12 to the home position.

The tab 66 engages the front flange 58 and disengages the rear flange 56 when the chair back 12 is pivoted in the forward direction 20 to the forward-leaning pivot position by a forward pivot force 90, as shown in FIG. 7. The tab 66 pivots the front flange 58 in the forward direction 20 away from the rear flange 56 which remains engaged with the flange stop 86, thereby forwardly loading the return spring 48.

A front pivot limiter 92 is arranged to limit pivotable movement of the chair back 12 in the forward direction 20, as shown in FIG. 7. The front flange 58 extends between the front pivot limiter 92 and the tab 66 so that the front pivot limiter 92 engages the front flange 58 to limit such forward pivotable movement. In the illustrated embodiment, the front pivot limiter 92 is a wall mounted to and extending radially inwardly from the shroud 53. The rear and front pivot limiters 87 and 92 are spaced circumferentially from one another.

The forwardly loaded return spring 48 returns the chair back 12 to the home position when the forward pivot force 90 is removed from the chair back 12. The front flange 58 engages the tab 66 and moves toward the rear flange 56 to apply a force thereto to pivot the chair back 12 in the rearward direction 18 to return the chair back 12 to the home position from the forwardly-leaning pivot position. The front flange 58 re-engages the flange stop 86 upon return of the chair back 12 to the home position.

A set of rear and front pivot limiters 87, 92 are also mounted to the shroud 53 of the right chair back mount 36, as shown in FIG. 4. They operate in the same manner with respect to the right return spring 50 as described in connection with the rear and front pivot limiters 87, 92 associated with the left return spring 48.

The rear pivot limiters 87 and the front pivot limiters 92 cooperate to define a pivot limiter device arranged to limit pivotable movement of the chair back 12 away from the home position in the rearward and forward directions 18, 20. The pivot limiter device thus provides means for limiting pivotable movement of the chair back 12 away from the home position in the rearward and forward directions 18, 20. 

1. A chair comprising a frame, a chair back mounted to the frame for pivotable movement of the chair back relative to the frame about a pivot axis from a home position in a first direction to a first pivot position and from the home position in a second direction opposite to the first direction to a second pivot position, the chair back including left and right sides and front and rear sides extending between the left and right sides, and return means for engaging at least one of the left and right sides of the chair back to pivot the chair back to return the chair back to the home position from the first and second pivot positions.
 2. The chair of claim 1, wherein the frame includes a spring mount and the return means includes a spring that is mounted to the spring mount and arranged to engage the at least one of the left and right sides.
 3. The chair of claim 2, wherein the spring includes a flange mount and relatively movable front and rear spring flanges extending radially outwardly from the flange mount, the at least one of the left and right sides includes a tab extending between the front and rear spring flanges, the rear spring flange is arranged to engage the tab and move toward the front spring flange to pivot the chair back from the first pivot position in the second direction to the home position, and the front spring flange is arranged to engage the tab and move toward the rear spring flange to pivot the chair back from the second pivot position in the first direction to the home position.
 4. The chair of claim 3, wherein the spring mount includes a flange mount base to which the flange mount is mounted and a flange stop extending radially outwardly from the flange mount base between the front and rear spring flanges for engagement therewith to stop movement thereof upon return of the chair back to the home position.
 5. The chair of claim 4, wherein the frame includes an axle, the at least one of the left and right sides is mounted to the axle for pivotable movement of the chair back about the pivot axis, and the flange mount base is formed to include an axle channel through which the axle extends.
 6. The chair of claim 3, further comprising pivot limiter means for limiting pivotable movement of the chair back away from the home position in the first direction and away from the home position in the second direction, the pivot limiter means includes a rear pivot limiter arranged to limit pivotable movement of the chair back away from the home position in the first direction and a front pivot limiter that is spaced circumferentially from the rear pivot limiter about the pivot axis and arranged to limit pivotable movement of the chair back away from the home position in the second direction, the rear spring flange extends between the rear pivot limiter and the tab, and the front spring flange extends between the front pivot limiter and the tab.
 7. The chair of claim 1, further comprising pivot limiter means for limiting pivotable movement of the chair back away from the home position in the first and second directions.
 8. The chair of claim 1, wherein the frame includes left and right chair back mounts which define the pivot axis, the left side of the chair back is mounted to the left chair back mount, the right side of the chair back is mounted to the right chair back mount, and the return means includes a left return spring that is mounted to the left chair back mount and arranged to engage the left side of the chair back and a right return spring that is mounted to the right chair back mount and arranged to engage the right side of the chair back.
 9. A chair comprising a frame, a chair back mounted to the frame for pivotable movement of the chair back relative to the frame about a pivot axis from a home position in a first direction to a first pivot position and from the home position in a second direction opposite to the first direction to a second pivot position, the chair back including left and right sides and front and rear sides extending between the left and right sides, and a chair back return device arranged to engage at least one of the left and right sides of the chair back to pivot the chair back to return the chair back to the home position from the first and second pivot positions.
 10. The chair of claim 9, wherein the chair back return device includes a return spring mounted to the frame and arranged to engage at least one of the left and right sides.
 11. The chair of claim 10, wherein the return spring includes a flange mount and relatively movable first and second spring flanges mounted to the flange mount, the at least one of the left and right sides includes a tab extending between the first and second spring flanges, the first spring flange is arranged to move relative to the second spring flange to apply a force to the tab to return the chair back to the home position from the first pivot position, and the second spring flange is arranged to move relative to the first spring flange to apply a force to the tab to return the chair back to the home position from the second pivot position.
 12. The chair of claim 11, wherein the frame includes a spring mount including a flange mount base to which the flange mount is mounted and a flange stop extending radially outwardly from the flange mount base between the first and second spring flanges for engagement therewith to stop movement thereof upon return of the chair back to the home position and the tab is positioned radially outwardly from the flange stop.
 13. The chair of claim 9, further comprising a pivot limiter device mounted to the frame and arranged to limit pivotable movement of the chair back away from the home position in the first and second directions.
 14. The chair of claim 13, further comprising a seat, wherein the frame includes a frame member to which the seat is mounted and a chair back mount that is mounted to a top portion of the frame member above the seat and includes an axle, the chair back is mounted to the axle for pivotable movement about the pivot axis, the chair back return device is mounted to the chair back mount, the pivot limiter device includes a first pivot limiter that is mounted to the chair back mount and arranged to limit pivotable movement of the chair back away from the home position in the first direction and a second pivot limiter that is mounted to the chair back mount and arranged to limit pivotable movement of the chair back away from the home position in the second direction.
 15. A chair comprising a frame, a chair back mounted to the frame for pivotable movement of the chair back relative to the frame about a pivot axis from a home position in a first direction to a first pivot position and from the home position in a second direction opposite to the first direction to a second pivot position, the chair back including a tab, and a return spring including a flange mount mounted to the frame and relatively movable first and second flanges mounted to and extending radially from the flange mount, the tab extending between the first and second flanges, the first flange being arranged to move relative to the second flange to apply a force to the tab to pivot the chair back to return the chair back to the home position from the first pivot position, the second flange being arranged to move relative to the first flange to apply a force to the tab to pivot the chair back to return the chair back to the home position from the second pivot position.
 16. The chair of claim 15, wherein the tab engages the first and second flanges when the chair back is positioned in the home position, the tab engages the first flange and disengages the second flange when the chair back is positioned in the first pivot position, and the tab engages the second flange and disengages the first flange when the chair back is positioned in the second pivot position.
 17. The chair of claim 15, wherein the frame includes a spring mount including a flange mount base and a flange stop, the flange mount is mounted to the flange mount base, and the flange stop extends radially from the flange mount base between the first and second flanges for engagement therewith to stop movement thereof upon return of the chair back to the home position.
 18. The chair of claim 17, wherein the frame includes an axle through which the pivot axis extends, the chair back is mounted to the axle for pivotable movement about the pivot axis, and the flange mount base is formed to include an axle channel through which the axle extends.
 19. The chair of claim 17, wherein the tab is positioned radially outwardly from the flange stop.
 20. The chair of claim 15, further comprising first and second pivot limiters mounted to the frame, wherein the first pivot limiter is arranged to engage the first flange to limit pivotable movement of the chair back in the first direction, and the second pivot limiter is arranged to engage the second flange to limit pivotable movement of the chair back in the second direction. 